one angle of a triangle is equal to the sum of the other two. Show that the sum of two exterior angles of the triangle is 180 degrees greater than the third

 Scott to deliver his packages = 30 times and -3 is his delivery time decrease per day.

Explanation: Since the line passes from the two points (3,21) and (6,12)-

as we know that the equation of a line passes through two points and is   ×

Thus equation of the line is ×(x-3)

= y-21=-3(x-3)

=y-21= -3 x+9

3 x +y=30, Which is the expression of Scott's delivery times on different days.

since according the graph- y-intercept= 30, which is the times in which Scott delivering his product initially.

Now, we have to find out Scott's delivery time decrease per day, for this slope of line 3x+y=30  is, m =

m= =-3

so required answer is,  slope=-3